**Forecast models and current atmospheric conditions point to a moderate high temperature in downtown Los Angeles on August 21, centering the market-implied odds on the 78–82°F range.** National Weather Service guidance and private ensembles show onshore marine flow and a persistent marine layer moderating inland heating, keeping afternoon maxima near or slightly below the late-August climatological average of ~84°F. Recent observations from the prior week, with highs mostly in the upper 70s to low 80s, reinforce trader consensus that 80–81°F is the most likely single-bin outcome at 47% implied probability. Key variables include the strength of the sea breeze and any overnight low-cloud cover that could limit daytime warming; minor model spread allows a secondary chance for 78–79°F (28.5%) if the marine influence strengthens. Higher bins above 82°F carry lower weight because no strong offshore flow or ridge amplification is projected in the next 24–48 hours. Resolution will hinge on the official NWS reading at the downtown station, with any last-minute shift in the 500 mb pattern or coastal stratus the primary catalyst that could move probabilities before markets close.